Extreme heat in Oregon

Extreme heat in Oregon

Dan Rubado, MPHEpidemiologist

Office of Environmental Public Health

700documented heat-related deaths in the US per year*

*more than all other weather-related deaths combined

1995 Chicago heat wave

5 days above 100°F apparent temperature739 deaths1,072

hospitalizations3,300 ED visits

14.6 heat-related death rate ratio for adults 65+

2006 California heat wave

11 consecutive days above 100°F 655 deaths1,182

hospitalizations16,166 ED visits

2003 heat wave in FranceHottest summer in Europe in the last 500

years

14,800 deaths

4.4 relative risk of heat-related death with no AC

15 consecutive days over 95°F

impacts of climate change

average summer time heat-related deaths are projected to increase, with larger increases in

mid-latitude cities.

oh no!are we headed for a fiery future of endless heat

waves?

110°F highest average temperature in the state

statewide climate statistics77°F average day time high temperature

50°F average night time low temperature

37.2 average number of days above 85°F


statewide heat-related illness stats

33.3 heat-related hospitalizations per year

111,277 total hospitalizations per year

1.8 heat-related deaths per year

11,300 total deaths per year

compared to:

Coos Bay climate normals96°F highest average temperature

coastal region68°F average day time high temperature



0 average number of days above 100°F

La Grande climate normals

eastern region80°F average day time high temperature




108°F highest average temperature

Medford climate normals

southwest region82°F average day time high temperature





Corvallis climate normals

Willamette valley region

77°F average day time high temperature





working hypothesishigh summer temperatures are associated with modest increases in deaths and hospital admissions, associations that vary regionally.

research questions1. what are the effects of heat on different

health outcomes in Oregon?2. how hot does it have to get before we see

big increases in heat-related illness?3. how do these effects vary regionally and for

vulnerable age groups?

N 4 miles

zip code boundary

Oregon zip codes

big town

small town

geographic center

population weighted center

weather station

w1 = 1 - d1/(d1 + d2)

w2 = 1 - d2/(d1 + d2)

d1 d

2

d3• daily

max temp

• daily min temp

weighted

average:

selected

stations

daily hospital admission

counts

daily mortality counts

Census zip code

population estimates

weather station data

analysis methodsPoisson regression model:log(count) = log(population) + α +

β(predictor)

outcome variablesheat-related hospitalizationsheat-related deaths

predictor variablestemperature variables and climate region

outcome predictorrate ratio (95%

CI) p-valueheat-related hospitalizations

max temp 3.66 (3.18, 4.22) <0.0001min temp 1.37 (1.12, 1.68) 0.0019

age 0-4 heat-related hospitalizations

max temp -- --min temp -- --

age 65+ heat-related hospitalizations

max temp 3.79 (3.15, 4.56) <0.0001min temp 1.33 (0.98, 1.80) 0.0648

initial resultssignificant

predictors:maximum temperatureminimum temperature

Min temp

Max

te

mp

r = 0.49p = <0.0001

coastal

eastern

southwestern

willamette

tmax6

5

tmax7

0

tmax7

5

tmax8

0

tmax8

5

tmax9

0

tmax9

5

tmax1

00

tmax1

051.06.0

11.016.021.026.0

Maximum Temperature Threshold and Heat Hospitalization Rate Ratio

Daily Maximum Temperature Threshold

Hea

t H

osp

Rate

Rat

io

tmin4

5tm

in50

tmin5

5tm

in60

tmin6

5tm

in70

tmin7

51.0

6.0

11.0

16.0

21.0

26.0

Minimum Temperature Threshold and Heat Hospitalization Rate Ratio

Daily Minimum Temperature Threshold

Hea

t H

osp

Rate

Rat

io

additional outcomes

hospitalizationsall non-injuryelectrolyte imbalancenephritiskidney failurecerebrovascular diseasecardiovascular disease

myocardial infarction

respiratory illnessasthma

deathsall non-injurycardiovascular diseaserespiratory illness

findingssignificant associations

all non-injury hospitalizations and deathselectrolyte imbalance hospitalizationsnephritis hospitalizationskidney failure hospitalizations

significant heat variablesmaximum temperatureminimum temperature (not deaths)

findings

outcome predictor

adjusted rate ratio (95%

CI) p-valueall non-injury hospitalizations

max temp 1.009 (1.006, 1.011) <0.0001min temp 0.992 (0.987, 0.997) 0.0011

Age 65+ non-injury hospitalizations

max temp 1.012 (1.007, 1.018) <0.0001min temp 0.987 (0.979, 0.995) 0.0011

electrolyte hospitalizations

max temp 1.056 (1.034, 1.077) <0.0001

min temp 1.047 (1.002, 1.094) 0.0392

all non-injury deaths max temp 1.009 (1.001, 1.017) 0.0231

all non-injury hospitalizations

electrolyte imbalance hospitalizations

all non-injury deaths

tmax6

5

tmax7

0

tmax7

5

tmax8

0

tmax

85

tmax9

0

tmax9

5

tmax1

00

tmax1

050.9000

1.4000

1.9000

2.4000

2.9000

Maximum Temperature Threshold and Electrolyte Hospitalization Rate Ratio

Daily Maximum Temperature ThresholdElec

trol

yte

Hos

pita

lizat

ion

Rat

e Ra

tio

tmin4

5tm

in50

tmin5

5tm

in60

tmin6

5tm

in70

tmin7

50.9000

1.4000

1.9000

2.4000

2.9000

Minimum Temperature Threshold and Electrolyte Hospitalization Rate Ratio

Daily Minimum Temperature ThresholdElec

trol

yte

Hos

pita

lizat

ion

Rat

e Ra

tio

summaryheat is not a major health issue in Oregon...there is an association between heat and illness that varies by regionthere are more heat-related deaths and illnesses than reportedsignificant health effects may occur below what the weather service uses to issue heat advisoriesimpacts were slightly greater on the 65+ age groupcontrary to popular belief, it does get hot in Oregonwith climate change, more hot weather is on the way

yet

thank you

Dan [email protected]

Extreme heat in Oregon

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